Overhead cable vibration testing device and testing method

Abstract

The invention discloses an overhead cable vibration testing device and a testing method. The device comprises an overhead cable test bench, a fiber grating sensor array, a vibration table, a fiber grating CCD(Charge Coupled Device) demodulation device and a PC(Personal Computer). The surface of an overhead cable on the overhead cable test bench is adhered with the fiber grating sensor array in theaxial direction. The vibration table is located below the overhead cable test bench. The bench top is hinged to the overhead cable. A control port is connected with the PC. The optical interface of the fiber grating CCD demodulation device is connected with the fiber grating sensor array. A data transmission port is connected with the PC. According to the overhead cable vibration test device andthe test method, the vibration of the overhead cable under a real environment is simulated through a vibration table excitation, a range adjustment and the initial tension of the cable, so as to systematically analyze the vibration characteristics of the overhead cable under various complex environments; by optimizing the test method and focusing on monitoring parts where faults are susceptible tohappen, the ultimate vibration parameter on the overhead cable can be accurately grabbed; and compared with an online cable monitoring scheme, the device is convenient to adjust, a high-altitude operation is avoided, and high scientific research value and operability are achieved.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensor vibration measurement, in particular to an overhead cable vibration test device and a test method, which are used for testing the vibration law and axial strain of the overhead cable under certain tension and various excitation conditions. Background technique [0002] In recent years, my country's power grid has achieved rapid development. Overhead transmission lines have gradually formed three major channels in the north, middle and south. The total length of transmission lines has exceeded 1.18 million kilometers. The scale and transmission capacity of the power grid have leapt to the first place in the world. However, overhead transmission lines have problems such as wide geographical distribution, complex operating conditions, and susceptibility to natural environmental influences and external damage. For example, overhead cable vibrations caused by breeze vibrations and galloping...

AI Technical Summary

Problems solved by technology

[0003] At present, the traditional cable vibration monitoring technology includes: a system composed of electronic sensors and electronic circuit processors. When the wire vibrates, the vibration information is transmitted to the remote processor through the electronic sensors, and finally the monitoring results are obtained. The method has the following disadvantages: 1) Its own weight will affect the accuracy of the measurement when it is installed on the wire; 2) It is easily affected by the strong magnetic field around the cable

But this method has obvious disadvantages: 1) The laser is transmitted in the air. If the refractive index of the air changes continuously under the condition of wind-induced vibration, it will affect the propagation of the laser; 2) The device can only measure one point after another. Can not monitor at the same time

The sensor structure of this method is complicated, the installation steps are various, preset parameters are required, and it is easily affected by temperature, and the measurement accuracy is not high; The method of continuous monitoring of domain reflection, in which the optical fiber is pre-laid in the overhead cable, when the cable vibrates, the phase between adjacent optical pulses changes, and the vibration of the cable can be obtained by demodulating the phase change

However, the signal of this method is weak, it is easily affected by the transmission line, the equipment is expensive and the accuracy is not high

In addition, the above two online monitoring methods have obvious disadvantages: 1) when welding and laying optical fiber sensors along the cable, high-altitude operations are required, the workload is high, the risk is high, and the operation is complicated; 2) this measurement is passive measurement, Need to wait for changes in the environment to cause cable vibration, it is difficult to monitor the upper limit of cable vibration strain, and it is difficult to realize the systematic research on the vibration characteristics of overhead cables

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